Self-supporting extension ladder



March 17, 1925.

1,529,898 E c LUCKE SELF SUPPORTING EXTENSION LADDER F iled Dec. 20, 1921 der,

Patented Mar. 17, 1925.

EDWARD o. LUCKE,

l 1,529,898 UNITED stares PATENT oFFicE;

0F Ln MARS, IOWA.

SELF-SUPFQRTIN EXTENSION LADDER,

Application filed December 20, 1921. Serial No. 523,749.

To all whom it may concern.

Be it known that I, EDWARD C. Looms, a citizen of the United States, and a resident of Le Mars, in the county of Plymouth and State of Iowa, have'invented a certain new and useful Self-Supporting Extension Ladof which the following is a specification. 7

The object of my invention'is to provide a self supporting extensible ladder of simple, durable and inexpensive construct-ion having its adjustable member so arranged that it may be easily and quickly manipulated.

A further object is to provide in a self supporting extensible ladder having a vertically adjustable member, improved means for supporting and locking the said adjustable member in a number of its positions of movement.

These and other objects will be apparent to those skilled in the art,

My invention consists in the construction, arrangement and combination of the-various parts of the device, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claim, and illustrated in the accompanying drawings, in which:

Figure 1 is an isometrical view of my improved ladder showing the manner in which it is set up when in use.

Figure 2 is a detail side elevation of a portion of the ladder showing the manner in which it may be folded when not in use.

Figure 3 is a detail sectional view of a portion of the ladder showing the manner in which the adjustable member is supported between the supporting members.

Figure 4 is a detail sectional view of the same showing the adjustable member being moved upwardly to a new position.

My extensible ladder comprises a pair of supporting members 10 having side rails 11 and rungs 12. These members 10 are similar in size and shape and may be of any length desired, and are for the primary purpose of supporting a vertically adjustable member 13, which I shall term an adjustable member.

This adjustable member is of the same width as the supporting members and is designed to be mounted in a vertical position when in use, while the supporting members 10 are arranged in oppositely inclined positions with the upper ends of their side rails 11 resting adjacent to the edges of the side rails of the adjustable members. per ends of the members 10 are beveled at 14 so that the said beveled portions will fit the edges of said exten'siblemember.

The upper ends of the members 10 are pivotally' secured to each other by means of inverted L-shaped plates 15. These plates 1'5 are secured to the side members 11 by means of bolts 16 and are mounted in such'a manner that the angular portions 17 are pivotally-connected to each other by means of a pivot 18 substantially midway between the beveled portions 14. This pivot memberis located in a line substantially even with the lower edges of the beveled portions 14 so that any downward movement of the mem-' her 13 by frictionally engaging the beveled portions 14 will cause Said beveled portions to grip the adjustable member.

Each end of the top rung 19 ofone of the members 10 is provided with :i'pivotally mounted brat-char 20. The free ends of the bars 20 are each provided with hook por ii on 21 designed to rest 'over the toprung 22 of the opposite member 10, as clearly shown in Figures 1 and 3.

' The central and upper edge of each of" the bars 20 is provided with a notch 23 so shaped as to fit'the bottom side of the rungs of the adjustable member in such a manner The u that the adjustable member may be held against downward movement by having one of its rungs resting in the notch 23, as clearly shown in Figure 3.

I The notch 23 is of such a depth that the downwardly extending portion of the adjustable member will be held againstmovem-ent toward or from the members 10 when one of its rungs restsin said notch.- The brace bar 20 therefore performs two functions, one to prevent downward movement of the adjustable member, and the other to prevent swinging movement of its free ends. I

The brace bar 20 is so arranged that as the adjustable member is moved upwardly in a vertical plane, the rung below the one which had rested in the notch 23 will engage the lower edge of the brace 20, as clearly shown in Figure 4, and will cause the said brace to be elevated and successively swung out of the way of each of the upwardly moving rungs.

When the adjustable member has been moved upwardly to the desired distance, the brace 20 will fallback into a horizontal position, aitefwhich the aldj u'stable member may be lowered a slight distance until the rung above the brace engages the notch 23. The adjustable member is thereby easily and quickly adjusted to its new position, and

will be firmly and reliably held.

I \Vhen it is desired to ir'old t he ladder, the

adjustable member is moved upwardly a lighwl t nq a e which th uses-129i f "ng uljyi ai dly to; '1 s itionsubstanr tially asshown in dotte nes in Figur elt,

, Y Wlllh the adjustable injinbenmay be v ple,

' ingposition Withinthe range of the ladder,

and, whleh nnay also be e asily and quickly fo lde d'jto lm ostf compact form, a and one in whioh', whe set upfo -bperation will rigidly support the extensible member.

I elaim. as my invention:

An improved self supporting extension ladder m priSing two supporting members,

eaehlformed of two side rails and eonnecting rungs, two hinges connecting their upper end, portions, 1 to the outer surface of the rails and extended inwardly and having its pivotal point between the rails, said parts being so shaped that when the supporting members are inclined upv'var y and toward each other, the

uppe i ends of the. will be parallel and spaced apart, adjustable member formed of two side rails anda number ot -.rung s, esid mils. be n i ifiglYt ttti w e S de d laeifi t e Z UPPQlP IIg 1 mm: f's', an' sv pa be Shep-ed tler-r. rangeq that when the si ppqrtinggmembers are spread the side ,ifails above the hinges il sk p tha id v,r f i e of .ithe a liul t b je member," and two combined supporting p ece ot metal havinga round-, pen ng at one, end to reoeive one of the rungisot one of the, supporting members and; be pivotally. supijorted thereby the other; end, being formed with a notch on its under surface to' receive oneof the rung-sot the opposite supporting member and the upper central -ppr;

tion ,being formed with a noteh toz receive ne of th lun s f the di'i i ehle tme i b 1: and "whereby the, adj held against downward movement,'and

h e e t ns,tm mbete nsett 1atlmstab' member are bracedagainst lateral movement ativ 4 0 v, ea e he Des l oines, Iowa, 

